New directory based system for channels

README.md

@@ -42,12 +42,29 @@ make
 
 ## Media
 
-The player scans `./media` for supported video files and converts filenames into channel names and current program titles.
+The player scans `./media` for channel directories. Each subdirectory is treated as one channel, and the supported video files inside it are played in alphabetical order as that channel's schedule.
 
-Current sample channels:
+Optional metadata can be provided with `description.txt` inside each channel directory:
 
-- `media/reading.mp4`
-- `media/computers.mp4`
+```txt
+name=Reading
+number=56
+description=Books, documentaries, and reading-focused programming.
+```
+
+Example layout:
+
+```txt
+media/
+  reading/
+    description.txt
+    01-intro.mp4
+    02-feature.mp4
+  computers/
+    description.txt
+    01-chronicles.mp4
+    02-demo.mp4
+```
 
 ## Fonts
 

src/channel.c

@@ -8,6 +8,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <strings.h>
+#include <sys/stat.h>
 
 static int has_supported_extension(const char *name) {
     const char *dot = strrchr(name, '.');
@@ -23,6 +24,11 @@ static int has_supported_extension(const char *name) {
            strcasecmp(dot, "m4v") == 0;
 }
 
+static int path_is_directory(const char *path) {
+    struct stat st;
+    return path && stat(path, &st) == 0 && S_ISDIR(st.st_mode);
+}
+
 static void trim_extension(char *text) {
     char *dot = strrchr(text, '.');
     if (dot) {
@@ -38,42 +44,45 @@ static void make_title_case(char *text) {
             new_word = 1;
             continue;
         }
-
         if (isspace((unsigned char) text[i])) {
             new_word = 1;
             continue;
         }
-
         text[i] = new_word ? (char) toupper((unsigned char) text[i]) : (char) tolower((unsigned char) text[i]);
         new_word = 0;
     }
 }
 
-static void derive_channel_name(const char *file_name, char *out, size_t out_size) {
-    char temp[128];
-    snprintf(temp, sizeof(temp), "%s", file_name);
+static void safe_copy(char *out, size_t out_size, const char *value) {
+    if (!out || out_size == 0) {
+        return;
+    }
+    snprintf(out, out_size, "%s", value ? value : "");
+}
+
+static void derive_display_name(const char *source, char *out, size_t out_size) {
+    char temp[256];
+    safe_copy(temp, sizeof(temp), source);
     trim_extension(temp);
-
-    if (strstr(temp, "reading") || strstr(temp, "reads")) {
-        snprintf(out, out_size, "Reading");
-        return;
-    }
-
-    if (strstr(temp, "computer") || strstr(temp, "half-life")) {
-        snprintf(out, out_size, "Computers");
-        return;
-    }
-
     make_title_case(temp);
-    snprintf(out, out_size, "%s", temp);
+    safe_copy(out, out_size, temp);
 }
 
 static void derive_program_title(const char *file_name, char *out, size_t out_size) {
-    char temp[128];
-    snprintf(temp, sizeof(temp), "%s", file_name);
-    trim_extension(temp);
-    make_title_case(temp);
-    snprintf(out, out_size, "%s", temp);
+    derive_display_name(file_name, out, out_size);
+}
+
+static char *trim_whitespace(char *text) {
+    char *end;
+    while (*text && isspace((unsigned char) *text)) {
+        text++;
+    }
+    end = text + strlen(text);
+    while (end > text && isspace((unsigned char) end[-1])) {
+        end--;
+    }
+    *end = '\0';
+    return text;
 }
 
 static double probe_duration_seconds(const char *file_path) {
@@ -92,10 +101,126 @@ static double probe_duration_seconds(const char *file_path) {
     return duration;
 }
 
+static int compare_programs(const void *left, const void *right) {
+    const ProgramEntry *a = (const ProgramEntry *) left;
+    const ProgramEntry *b = (const ProgramEntry *) right;
+    return strcmp(a->file_name, b->file_name);
+}
+
 static int compare_channels(const void *left, const void *right) {
     const Channel *a = (const Channel *) left;
     const Channel *b = (const Channel *) right;
-    return strcmp(a->file_name, b->file_name);
+    int a_has_number = a->number > 0;
+    int b_has_number = b->number > 0;
+
+    if (a_has_number && b_has_number && a->number != b->number) {
+        return a->number - b->number;
+    }
+    if (a_has_number != b_has_number) {
+        return a_has_number ? -1 : 1;
+    }
+    return strcmp(a->name, b->name);
+}
+
+static int parse_channel_metadata(Channel *channel, const char *channel_dir) {
+    char metadata_path[PATH_MAX];
+    FILE *file;
+    char line[512];
+
+    snprintf(metadata_path, sizeof(metadata_path), "%s/description.txt", channel_dir);
+    file = fopen(metadata_path, "r");
+    if (!file) {
+        return 0;
+    }
+
+    while (fgets(line, sizeof(line), file) != NULL) {
+        char *equals = strchr(line, '=');
+        char *key;
+        char *value;
+        if (!equals) {
+            continue;
+        }
+        *equals = '\0';
+        key = trim_whitespace(line);
+        value = trim_whitespace(equals + 1);
+        if (strcasecmp(key, "name") == 0) {
+            safe_copy(channel->name, sizeof(channel->name), value);
+        } else if (strcasecmp(key, "number") == 0) {
+            channel->number = atoi(value);
+        } else if (strcasecmp(key, "description") == 0) {
+            safe_copy(channel->description, sizeof(channel->description), value);
+        }
+    }
+
+    fclose(file);
+    return 0;
+}
+
+static int load_channel_programs(Channel *channel, const char *channel_dir) {
+    DIR *directory;
+    struct dirent *entry;
+    int capacity = 8;
+
+    directory = opendir(channel_dir);
+    if (!directory) {
+        return -1;
+    }
+
+    channel->programs = calloc((size_t) capacity, sizeof(ProgramEntry));
+    if (!channel->programs) {
+        closedir(directory);
+        return -1;
+    }
+
+    while ((entry = readdir(directory)) != NULL) {
+        ProgramEntry *program;
+        char file_path[PATH_MAX];
+
+        if (entry->d_name[0] == '.' || !has_supported_extension(entry->d_name)) {
+            continue;
+        }
+
+        snprintf(file_path, sizeof(file_path), "%s/%s", channel_dir, entry->d_name);
+        if (path_is_directory(file_path)) {
+            continue;
+        }
+
+        if (channel->program_count == capacity) {
+            ProgramEntry *resized;
+            capacity *= 2;
+            resized = realloc(channel->programs, (size_t) capacity * sizeof(ProgramEntry));
+            if (!resized) {
+                closedir(directory);
+                return -1;
+            }
+            channel->programs = resized;
+        }
+
+        program = &channel->programs[channel->program_count];
+        memset(program, 0, sizeof(*program));
+        safe_copy(program->file_name, sizeof(program->file_name), entry->d_name);
+        safe_copy(program->file_path, sizeof(program->file_path), file_path);
+        derive_program_title(entry->d_name, program->program_title, sizeof(program->program_title));
+        program->duration_seconds = probe_duration_seconds(program->file_path);
+        channel->program_count += 1;
+    }
+
+    closedir(directory);
+
+    if (channel->program_count == 0) {
+        free(channel->programs);
+        channel->programs = NULL;
+        return 0;
+    }
+
+    qsort(channel->programs, (size_t) channel->program_count, sizeof(ProgramEntry), compare_programs);
+    channel->total_duration_seconds = 0.0;
+    for (int i = 0; i < channel->program_count; ++i) {
+        channel->programs[i].start_offset_seconds = channel->total_duration_seconds;
+        channel->total_duration_seconds += channel->programs[i].duration_seconds;
+    }
+
+    return channel->program_count;
 }
 
 int channel_list_load(ChannelList *list, const char *media_dir) {
@@ -122,8 +247,15 @@ int channel_list_load(ChannelList *list, const char *media_dir) {
 
     while ((entry = readdir(directory)) != NULL) {
         Channel *channel;
+        char channel_dir[PATH_MAX];
+        int load_result;
 
-        if (entry->d_name[0] == '.' || !has_supported_extension(entry->d_name)) {
+        if (entry->d_name[0] == '.') {
+            continue;
+        }
+
+        snprintf(channel_dir, sizeof(channel_dir), "%s/%s", media_dir, entry->d_name);
+        if (!path_is_directory(channel_dir)) {
             continue;
         }
 
@@ -141,12 +273,20 @@ int channel_list_load(ChannelList *list, const char *media_dir) {
 
         channel = &list->items[list->count];
         memset(channel, 0, sizeof(*channel));
-        channel->number = 50 + list->count;
-        snprintf(channel->file_name, sizeof(channel->file_name), "%s", entry->d_name);
-        snprintf(channel->file_path, sizeof(channel->file_path), "%s/%s", media_dir, entry->d_name);
-        derive_channel_name(entry->d_name, channel->name, sizeof(channel->name));
-        derive_program_title(entry->d_name, channel->program_title, sizeof(channel->program_title));
-        channel->duration_seconds = probe_duration_seconds(channel->file_path);
+        derive_display_name(entry->d_name, channel->name, sizeof(channel->name));
+        safe_copy(channel->description, sizeof(channel->description), "Local programming lineup.");
+        parse_channel_metadata(channel, channel_dir);
+        load_result = load_channel_programs(channel, channel_dir);
+        if (load_result < 0) {
+            closedir(directory);
+            channel_list_destroy(list);
+            return -1;
+        }
+        if (load_result == 0 || channel->total_duration_seconds <= 0.0) {
+            free(channel->programs);
+            memset(channel, 0, sizeof(*channel));
+            continue;
+        }
         list->count += 1;
     }
 
@@ -159,7 +299,9 @@ int channel_list_load(ChannelList *list, const char *media_dir) {
 
     qsort(list->items, (size_t) list->count, sizeof(Channel), compare_channels);
     for (int i = 0; i < list->count; ++i) {
-        list->items[i].number = 50 + i;
+        if (list->items[i].number <= 0) {
+            list->items[i].number = 50 + i;
+        }
     }
 
     return list->count;
@@ -170,6 +312,11 @@ void channel_list_destroy(ChannelList *list) {
         return;
     }
 
+    if (list->items) {
+        for (int i = 0; i < list->count; ++i) {
+            free(list->items[i].programs);
+        }
+    }
     free(list->items);
     list->items = NULL;
     list->count = 0;
@@ -178,7 +325,7 @@ void channel_list_destroy(ChannelList *list) {
 double channel_live_position(const Channel *channel, time_t app_start_time, time_t now) {
     double elapsed;
 
-    if (!channel || channel->duration_seconds <= 0.0) {
+    if (!channel || channel->total_duration_seconds <= 0.0) {
         return 0.0;
     }
 
@@ -187,13 +334,13 @@ double channel_live_position(const Channel *channel, time_t app_start_time, time
         elapsed = 0.0;
     }
 
-    return fmod(elapsed, channel->duration_seconds);
+    return fmod(elapsed, channel->total_duration_seconds);
 }
 
 double channel_live_position_precise(const Channel *channel, Uint64 app_start_ticks, Uint64 now_ticks) {
     double elapsed;
 
-    if (!channel || channel->duration_seconds <= 0.0) {
+    if (!channel || channel->total_duration_seconds <= 0.0) {
         return 0.0;
     }
 
@@ -202,5 +349,44 @@ double channel_live_position_precise(const Channel *channel, Uint64 app_start_ti
     }
 
     elapsed = (double) (now_ticks - app_start_ticks) / 1000.0;
-    return fmod(elapsed, channel->duration_seconds);
+    return fmod(elapsed, channel->total_duration_seconds);
+}
+
+const ProgramEntry *channel_program_at_index(const Channel *channel, int program_index) {
+    if (!channel || program_index < 0 || program_index >= channel->program_count) {
+        return NULL;
+    }
+    return &channel->programs[program_index];
+}
+
+const ProgramEntry *channel_resolve_program(const Channel *channel,
+                                            Uint64 app_start_ticks,
+                                            Uint64 now_ticks,
+                                            double *program_seek_seconds,
+                                            int *program_index) {
+    double channel_offset;
+
+    if (!channel || channel->program_count == 0 || channel->total_duration_seconds <= 0.0) {
+        return NULL;
+    }
+
+    channel_offset = channel_live_position_precise(channel, app_start_ticks, now_ticks);
+    for (int i = 0; i < channel->program_count; ++i) {
+        const ProgramEntry *program = &channel->programs[i];
+        double end_offset = program->start_offset_seconds + program->duration_seconds;
+        if (channel_offset < end_offset || i == channel->program_count - 1) {
+            if (program_seek_seconds) {
+                *program_seek_seconds = channel_offset - program->start_offset_seconds;
+                if (*program_seek_seconds < 0.0) {
+                    *program_seek_seconds = 0.0;
+                }
+            }
+            if (program_index) {
+                *program_index = i;
+            }
+            return program;
+        }
+    }
+
+    return &channel->programs[0];
 }

src/channel.h

@@ -8,11 +8,19 @@
 typedef struct Channel {
     int number;
     char name[64];
+    char description[256];
+    double total_duration_seconds;
+    struct ProgramEntry *programs;
+    int program_count;
+} Channel;
+
+typedef struct ProgramEntry {
     char file_path[PATH_MAX];
     char file_name[128];
     char program_title[128];
     double duration_seconds;
-} Channel;
+    double start_offset_seconds;
+} ProgramEntry;
 
 typedef struct ChannelList {
     Channel *items;
@@ -23,5 +31,11 @@ int channel_list_load(ChannelList *list, const char *media_dir);
 void channel_list_destroy(ChannelList *list);
 double channel_live_position(const Channel *channel, time_t app_start_time, time_t now);
 double channel_live_position_precise(const Channel *channel, Uint64 app_start_ticks, Uint64 now_ticks);
+const ProgramEntry *channel_resolve_program(const Channel *channel,
+                                            Uint64 app_start_ticks,
+                                            Uint64 now_ticks,
+                                            double *program_seek_seconds,
+                                            int *program_index);
+const ProgramEntry *channel_program_at_index(const Channel *channel, int program_index);
 
 #endif

src/player.c

@@ -184,6 +184,7 @@ static int queue_audio_frame(Player *player,
                             AVCodecContext *audio_codec_context,
                             AVRational audio_time_base,
                             AVFrame *audio_frame,
+                            double pts_base_offset,
                             int *queued_any_audio) {
     uint8_t **converted_data = NULL;
     int out_rate;
@@ -269,7 +270,7 @@ static int queue_audio_frame(Player *player,
 
     audio_pts = audio_frame->best_effort_timestamp == AV_NOPTS_VALUE
         ? NAN
-        : audio_frame->best_effort_timestamp * av_q2d(audio_time_base);
+        : pts_base_offset + (audio_frame->best_effort_timestamp * av_q2d(audio_time_base));
     frame_duration = (double) sample_count / (double) out_rate;
 
     queued_limit = (int) (player_audio_bytes_per_second(player) * 0.18);
@@ -303,187 +304,211 @@ static int queue_audio_frame(Player *player,
     return 0;
 }
 
+typedef struct DecodeContext {
+    AVFormatContext *format_context;
+    AVCodecContext *video_codec_context;
+    AVCodecContext *audio_codec_context;
+    struct SwsContext *sws_context;
+    SwrContext *swr_context;
+    AVPacket *packet;
+    AVFrame *decoded_frame;
+    AVFrame *audio_frame;
+    AVRational video_time_base;
+    AVRational audio_time_base;
+    int video_stream_index;
+    int audio_stream_index;
+} DecodeContext;
+
+static void decode_context_reset(DecodeContext *ctx) {
+    if (!ctx) {
+        return;
+    }
+    if (ctx->packet) av_packet_free(&ctx->packet);
+    if (ctx->decoded_frame) av_frame_free(&ctx->decoded_frame);
+    if (ctx->audio_frame) av_frame_free(&ctx->audio_frame);
+    if (ctx->video_codec_context) avcodec_free_context(&ctx->video_codec_context);
+    if (ctx->audio_codec_context) avcodec_free_context(&ctx->audio_codec_context);
+    if (ctx->format_context) avformat_close_input(&ctx->format_context);
+    if (ctx->sws_context) sws_freeContext(ctx->sws_context);
+    if (ctx->swr_context) swr_free(&ctx->swr_context);
+    memset(ctx, 0, sizeof(*ctx));
+    ctx->video_stream_index = -1;
+    ctx->audio_stream_index = -1;
+}
+
+static int decode_context_open(DecodeContext *ctx, const ProgramEntry *program, Player *player) {
+    const AVCodec *video_codec = NULL;
+    const AVCodec *audio_codec = NULL;
+
+    decode_context_reset(ctx);
+    ctx->video_stream_index = -1;
+    ctx->audio_stream_index = -1;
+
+    if (avformat_open_input(&ctx->format_context, program->file_path, NULL, NULL) < 0) {
+        player_set_error(player, "Unable to open media file");
+        return -1;
+    }
+    if (avformat_find_stream_info(ctx->format_context, NULL) < 0) {
+        player_set_error(player, "Unable to read stream metadata");
+        return -1;
+    }
+    for (unsigned int i = 0; i < ctx->format_context->nb_streams; ++i) {
+        if (ctx->format_context->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
+            ctx->video_stream_index = (int) i;
+        } else if (ctx->format_context->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO && ctx->audio_stream_index < 0) {
+            ctx->audio_stream_index = (int) i;
+        }
+    }
+    if (ctx->video_stream_index < 0) {
+        player_set_error(player, "No video stream found");
+        return -1;
+    }
+
+    video_codec = avcodec_find_decoder(ctx->format_context->streams[ctx->video_stream_index]->codecpar->codec_id);
+    if (!video_codec) {
+        player_set_error(player, "Unsupported video codec");
+        return -1;
+    }
+    ctx->video_codec_context = avcodec_alloc_context3(video_codec);
+    if (!ctx->video_codec_context ||
+        avcodec_parameters_to_context(ctx->video_codec_context, ctx->format_context->streams[ctx->video_stream_index]->codecpar) < 0 ||
+        avcodec_open2(ctx->video_codec_context, video_codec, NULL) < 0) {
+        player_set_error(player, "Unable to initialize decoder");
+        return -1;
+    }
+
+    if (ctx->audio_stream_index >= 0) {
+        audio_codec = avcodec_find_decoder(ctx->format_context->streams[ctx->audio_stream_index]->codecpar->codec_id);
+        if (audio_codec) {
+            ctx->audio_codec_context = avcodec_alloc_context3(audio_codec);
+            if (!ctx->audio_codec_context ||
+                avcodec_parameters_to_context(ctx->audio_codec_context, ctx->format_context->streams[ctx->audio_stream_index]->codecpar) < 0 ||
+                avcodec_open2(ctx->audio_codec_context, audio_codec, NULL) < 0) {
+                player_set_error(player, "Unable to initialize audio decoder");
+                return -1;
+            }
+            ctx->audio_time_base = ctx->format_context->streams[ctx->audio_stream_index]->time_base;
+        }
+    }
+
+    ctx->packet = av_packet_alloc();
+    ctx->decoded_frame = av_frame_alloc();
+    ctx->audio_frame = av_frame_alloc();
+    if (!ctx->packet || !ctx->decoded_frame || !ctx->audio_frame) {
+        player_set_error(player, "Unable to allocate FFmpeg frame buffers");
+        return -1;
+    }
+
+    ctx->video_time_base = ctx->format_context->streams[ctx->video_stream_index]->time_base;
+    ctx->sws_context = sws_getContext(ctx->video_codec_context->width,
+                                      ctx->video_codec_context->height,
+                                      ctx->video_codec_context->pix_fmt,
+                                      ctx->video_codec_context->width,
+                                      ctx->video_codec_context->height,
+                                      AV_PIX_FMT_YUV420P,
+                                      SWS_BILINEAR,
+                                      NULL,
+                                      NULL,
+                                      NULL);
+    if (!ctx->sws_context) {
+        player_set_error(player, "Unable to initialize scaler");
+        return -1;
+    }
+
+    player->has_audio_stream = ctx->audio_codec_context != NULL;
+    return 0;
+}
+
 static int decode_thread_main(void *userdata) {
     DecoderThreadArgs *args = (DecoderThreadArgs *) userdata;
     Player *player = args->player;
     const Channel *channel = args->channel;
-    AVFormatContext *format_context = NULL;
-    AVCodecContext *codec_context = NULL;
-    AVCodecContext *audio_codec_context = NULL;
-    AVPacket *packet = NULL;
-    AVFrame *decoded_frame = NULL;
-    AVFrame *audio_frame = NULL;
-    struct SwsContext *sws_context = NULL;
-    SwrContext *swr_context = NULL;
-    const AVCodec *codec = NULL;
-    const AVCodec *audio_codec = NULL;
-    int video_stream_index = -1;
-    int audio_stream_index = -1;
-    int rc = -1;
+    DecodeContext ctx;
+    const ProgramEntry *program;
+    int current_program_index = 0;
     double seek_seconds = 0.0;
-    AVRational time_base;
-    AVRational audio_time_base = {0};
     int queued_any_audio = 0;
     int queued_first_video = 0;
+    int rc = -1;
 
-    #define MAYBE_MARK_PREROLL_READY() \
-        do { \
-            if (queued_first_video && (queued_any_audio || !player->has_audio_stream)) { \
-                player_mark_preroll_ready(player); \
-            } \
-        } while (0)
+    #define MAYBE_MARK_PREROLL_READY() do { if (queued_first_video && (queued_any_audio || !player->has_audio_stream)) { player_mark_preroll_ready(player); } } while (0)
 
+    memset(&ctx, 0, sizeof(ctx));
+    ctx.video_stream_index = -1;
+    ctx.audio_stream_index = -1;
     free(args);
 
-    if (avformat_open_input(&format_context, channel->file_path, NULL, NULL) < 0) {
-        player_set_error(player, "Unable to open media file");
+    program = channel_resolve_program(channel, player->app_start_ticks, SDL_GetTicks64(), &seek_seconds, &current_program_index);
+    if (!program || decode_context_open(&ctx, program, player) != 0) {
+        decode_context_reset(&ctx);
         return -1;
     }
 
-    if (avformat_find_stream_info(format_context, NULL) < 0) {
-        player_set_error(player, "Unable to read stream metadata");
-        goto cleanup;
-    }
-
-    for (unsigned int i = 0; i < format_context->nb_streams; ++i) {
-        if (format_context->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
-            video_stream_index = (int) i;
-        } else if (format_context->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO && audio_stream_index < 0) {
-            audio_stream_index = (int) i;
+    if (seek_seconds > 0.0) {
+        int64_t seek_target = (int64_t) (seek_seconds / av_q2d(ctx.video_time_base));
+        avformat_seek_file(ctx.format_context, ctx.video_stream_index, INT64_MIN, seek_target, INT64_MAX, 0);
+        avcodec_flush_buffers(ctx.video_codec_context);
+        if (ctx.audio_codec_context) {
+            avcodec_flush_buffers(ctx.audio_codec_context);
         }
     }
-
-    if (video_stream_index < 0) {
-        player_set_error(player, "No video stream found");
-        goto cleanup;
-    }
-
-    codec = avcodec_find_decoder(format_context->streams[video_stream_index]->codecpar->codec_id);
-    if (!codec) {
-        player_set_error(player, "Unsupported video codec");
-        goto cleanup;
-    }
-
-    codec_context = avcodec_alloc_context3(codec);
-    if (!codec_context) {
-        player_set_error(player, "Unable to allocate codec context");
-        goto cleanup;
-    }
-
-    if (avcodec_parameters_to_context(codec_context, format_context->streams[video_stream_index]->codecpar) < 0 ||
-        avcodec_open2(codec_context, codec, NULL) < 0) {
-        player_set_error(player, "Unable to initialize decoder");
-        goto cleanup;
-    }
-
-    if (audio_stream_index >= 0) {
-        audio_codec = avcodec_find_decoder(format_context->streams[audio_stream_index]->codecpar->codec_id);
-        if (audio_codec) {
-            audio_codec_context = avcodec_alloc_context3(audio_codec);
-            if (!audio_codec_context) {
-                player_set_error(player, "Unable to allocate audio decoder context");
-                goto cleanup;
-            }
-
-            if (avcodec_parameters_to_context(audio_codec_context, format_context->streams[audio_stream_index]->codecpar) < 0 ||
-                avcodec_open2(audio_codec_context, audio_codec, NULL) < 0) {
-                player_set_error(player, "Unable to initialize audio decoder");
-                goto cleanup;
-            }
-
-            audio_time_base = format_context->streams[audio_stream_index]->time_base;
-        }
-    }
-
-    decoded_frame = av_frame_alloc();
-    audio_frame = av_frame_alloc();
-    packet = av_packet_alloc();
-    if (!decoded_frame || !audio_frame || !packet) {
-        player_set_error(player, "Unable to allocate FFmpeg frame buffers");
-        goto cleanup;
-    }
-
-    time_base = format_context->streams[video_stream_index]->time_base;
-    player->has_audio_stream = audio_codec_context != NULL;
-    sws_context = sws_getContext(codec_context->width,
-                                 codec_context->height,
-                                 codec_context->pix_fmt,
-                                 codec_context->width,
-                                 codec_context->height,
-                                 AV_PIX_FMT_YUV420P,
-                                 SWS_BILINEAR,
-                                 NULL,
-                                 NULL,
-                                 NULL);
-    if (!sws_context) {
-        player_set_error(player, "Unable to initialize scaler");
-        goto cleanup;
-    }
-
-    seek_seconds = channel_live_position_precise(channel, player->app_start_ticks, SDL_GetTicks64());
-    if (channel->duration_seconds > 0.0) {
-        int64_t seek_target = (int64_t) (seek_seconds / av_q2d(time_base));
-        avformat_seek_file(format_context, video_stream_index, INT64_MIN, seek_target, INT64_MAX, 0);
-        avcodec_flush_buffers(codec_context);
-        if (audio_codec_context) {
-            avcodec_flush_buffers(audio_codec_context);
-        }
-        player_clear_audio(player);
-    }
+    player_clear_audio(player);
 
     while (!should_stop(player)) {
-        if (av_read_frame(format_context, packet) < 0) {
-            if (channel->duration_seconds > 0.0) {
-                seek_seconds = 0.0;
-                avformat_seek_file(format_context, video_stream_index, INT64_MIN, 0, INT64_MAX, 0);
-                avcodec_flush_buffers(codec_context);
-                if (audio_codec_context) {
-                    avcodec_flush_buffers(audio_codec_context);
-                }
-                player_clear_audio(player);
-                continue;
+        if (av_read_frame(ctx.format_context, ctx.packet) < 0) {
+            current_program_index = (current_program_index + 1) % channel->program_count;
+            program = channel_program_at_index(channel, current_program_index);
+            queued_any_audio = 0;
+            queued_first_video = 0;
+            if (!program || decode_context_open(&ctx, program, player) != 0) {
+                goto cleanup;
             }
-            break;
+            continue;
         }
 
-        if (packet->stream_index == audio_stream_index && audio_codec_context) {
-            if (avcodec_send_packet(audio_codec_context, packet) >= 0) {
+        if (ctx.packet->stream_index == ctx.audio_stream_index && ctx.audio_codec_context) {
+            if (avcodec_send_packet(ctx.audio_codec_context, ctx.packet) >= 0) {
                 while (!should_stop(player)) {
-                    int receive_audio = avcodec_receive_frame(audio_codec_context, audio_frame);
+                    int receive_audio = avcodec_receive_frame(ctx.audio_codec_context, ctx.audio_frame);
                     if (receive_audio == AVERROR(EAGAIN) || receive_audio == AVERROR_EOF) {
                         break;
                     }
                     if (receive_audio < 0) {
                         player_set_error(player, "Audio decode failed");
-                        av_packet_unref(packet);
+                        av_packet_unref(ctx.packet);
                         goto cleanup;
                     }
-                    if (queue_audio_frame(player, &swr_context, audio_codec_context, audio_time_base, audio_frame, &queued_any_audio) != 0) {
-                        av_packet_unref(packet);
+                    if (queue_audio_frame(player,
+                                          &ctx.swr_context,
+                                          ctx.audio_codec_context,
+                                          ctx.audio_time_base,
+                                          ctx.audio_frame,
+                                          program->start_offset_seconds,
+                                          &queued_any_audio) != 0) {
+                        av_packet_unref(ctx.packet);
                         goto cleanup;
                     }
                     MAYBE_MARK_PREROLL_READY();
-                    av_frame_unref(audio_frame);
+                    av_frame_unref(ctx.audio_frame);
                 }
             }
-            av_packet_unref(packet);
+            av_packet_unref(ctx.packet);
             continue;
         }
 
-        if (packet->stream_index != video_stream_index) {
-            av_packet_unref(packet);
+        if (ctx.packet->stream_index != ctx.video_stream_index) {
+            av_packet_unref(ctx.packet);
             continue;
         }
-
-        if (avcodec_send_packet(codec_context, packet) < 0) {
-            av_packet_unref(packet);
+        if (avcodec_send_packet(ctx.video_codec_context, ctx.packet) < 0) {
+            av_packet_unref(ctx.packet);
             continue;
         }
-        av_packet_unref(packet);
+        av_packet_unref(ctx.packet);
 
         while (!should_stop(player)) {
             double frame_seconds;
-            int receive = avcodec_receive_frame(codec_context, decoded_frame);
+            int receive = avcodec_receive_frame(ctx.video_codec_context, ctx.decoded_frame);
             if (receive == AVERROR(EAGAIN) || receive == AVERROR_EOF) {
                 break;
             }
@@ -492,9 +517,9 @@ static int decode_thread_main(void *userdata) {
                 goto cleanup;
             }
 
-            frame_seconds = decoded_frame->best_effort_timestamp == AV_NOPTS_VALUE
-                ? seek_seconds
-                : decoded_frame->best_effort_timestamp * av_q2d(time_base);
+            frame_seconds = ctx.decoded_frame->best_effort_timestamp == AV_NOPTS_VALUE
+                ? program->start_offset_seconds + seek_seconds
+                : program->start_offset_seconds + (ctx.decoded_frame->best_effort_timestamp * av_q2d(ctx.video_time_base));
 
             {
                 FrameData frame = {0};
@@ -502,20 +527,14 @@ static int decode_thread_main(void *userdata) {
                 int dest_linesize[4] = {0};
                 int image_size;
 
-                frame.width = codec_context->width;
-                frame.height = codec_context->height;
+                frame.width = ctx.video_codec_context->width;
+                frame.height = ctx.video_codec_context->height;
                 frame.pts_seconds = frame_seconds;
-                image_size = av_image_alloc(dest_data,
-                                            dest_linesize,
-                                            frame.width,
-                                            frame.height,
-                                            AV_PIX_FMT_YUV420P,
-                                            1);
+                image_size = av_image_alloc(dest_data, dest_linesize, frame.width, frame.height, AV_PIX_FMT_YUV420P, 1);
                 if (image_size < 0) {
                     player_set_error(player, "Unable to allocate frame buffer");
                     goto cleanup;
                 }
-
                 frame.buffer = dest_data[0];
                 frame.plane_y = dest_data[0];
                 frame.plane_u = dest_data[1];
@@ -523,18 +542,15 @@ static int decode_thread_main(void *userdata) {
                 frame.pitch_y = dest_linesize[0];
                 frame.pitch_u = dest_linesize[1];
                 frame.pitch_v = dest_linesize[2];
-
-                sws_scale(sws_context,
-                          (const uint8_t *const *) decoded_frame->data,
-                          decoded_frame->linesize,
+                sws_scale(ctx.sws_context,
+                          (const uint8_t *const *) ctx.decoded_frame->data,
+                          ctx.decoded_frame->linesize,
                           0,
-                          codec_context->height,
+                          ctx.video_codec_context->height,
                           dest_data,
                           dest_linesize);
                 frame_queue_push(&player->frame_queue, &frame);
-                if (!queued_first_video) {
-                    queued_first_video = 1;
-                }
+                queued_first_video = 1;
                 MAYBE_MARK_PREROLL_READY();
             }
         }
@@ -543,30 +559,7 @@ static int decode_thread_main(void *userdata) {
     rc = 0;
 
 cleanup:
-    if (packet) {
-        av_packet_free(&packet);
-    }
-    if (decoded_frame) {
-        av_frame_free(&decoded_frame);
-    }
-    if (audio_frame) {
-        av_frame_free(&audio_frame);
-    }
-    if (codec_context) {
-        avcodec_free_context(&codec_context);
-    }
-    if (audio_codec_context) {
-        avcodec_free_context(&audio_codec_context);
-    }
-    if (format_context) {
-        avformat_close_input(&format_context);
-    }
-    if (sws_context) {
-        sws_freeContext(sws_context);
-    }
-    if (swr_context) {
-        swr_free(&swr_context);
-    }
+    decode_context_reset(&ctx);
     player->has_audio_stream = 0;
     return rc;
 

src/ui.c

@@ -389,7 +389,8 @@ static void draw_info_panel(SDL_Renderer *renderer,
     char description[384];
     time_t start_time;
     time_t end_time;
-    double live_position;
+    double program_seek;
+    const ProgramEntry *program;
 
     if (!rect || !selected_channel) {
         return;
@@ -402,23 +403,24 @@ static void draw_info_panel(SDL_Renderer *renderer,
     draw_panel_bevel(renderer, rect);
     stroke_rect(renderer, rect, COLOR_BORDER_DARK);
 
-    live_position = channel_live_position_precise(selected_channel, app_start_ticks, now_ticks);
-    start_time = now_wall - (time_t) live_position;
-    end_time = start_time + (time_t) selected_channel->duration_seconds;
+    program = channel_resolve_program(selected_channel, app_start_ticks, now_ticks, &program_seek, NULL);
+    if (!program) {
+        return;
+    }
+    start_time = now_wall - (time_t) program_seek;
+    end_time = start_time + (time_t) program->duration_seconds;
     format_time_compact(time_range, sizeof(time_range), start_time);
     format_time_compact(end_text, sizeof(end_text), end_time);
     strncat(time_range, " - ", sizeof(time_range) - strlen(time_range) - 1);
     strncat(time_range, end_text, sizeof(time_range) - strlen(time_range) - 1);
     snprintf(description,
              sizeof(description),
-             "Channel %d presents %s. Source: %s.",
-             selected_channel->number,
-             selected_channel->program_title,
-             selected_channel->file_name);
+             "%s",
+             selected_channel->description[0] != '\0' ? selected_channel->description : "Local programming lineup.");
 
     clip_rect = (SDL_Rect){rect->x + 16, rect->y + 12, rect->w - 32, rect->h - 24};
     draw_text_clipped(renderer, fonts->large, selected_channel->name, &clip_rect, rect->x + 18, rect->y + 44, COLOR_PANEL_TEXT);
-    draw_text_clipped(renderer, fonts->medium, selected_channel->program_title, &clip_rect, rect->x + 18, rect->y + 88, COLOR_PANEL_TEXT);
+    draw_text_clipped(renderer, fonts->medium, program->program_title, &clip_rect, rect->x + 18, rect->y + 88, COLOR_PANEL_TEXT);
     draw_text_clipped(renderer, fonts->small, time_range, &clip_rect, rect->x + 18, rect->y + 124, COLOR_PANEL_TEXT);
     draw_text_clipped(renderer, fonts->small, description, &clip_rect, rect->x + 18, rect->y + 148, COLOR_PANEL_TEXT);
 }
@@ -581,15 +583,27 @@ void ui_render_guide(SDL_Renderer *renderer,
 
         {
             const Channel *channel = &channels->items[channel_index];
-            double live_position = channel_live_position_precise(channel, app_start_ticks, now_ticks);
+            double live_position = 0.0;
+            double program_seek = 0.0;
+            const ProgramEntry *program = channel_resolve_program(channel, app_start_ticks, now_ticks, &program_seek, NULL);
             time_t guide_view_start_time = now_wall - (30 * 60);
             time_t program_start_time = now_wall - (time_t) live_position;
-            int block_x = GUIDE_X_START + (int) (((double) (program_start_time - guide_view_start_time)) / 60.0 * pixels_per_minute);
-            int block_w = (int) ((channel->duration_seconds / 60.0) * pixels_per_minute);
-            SDL_Rect block = {block_x, timeline_rect.y + 4, SDL_max(block_w, 48), timeline_rect.h - 8};
+            int block_x = GUIDE_X_START;
+            int block_w = 48;
+            SDL_Rect block = {GUIDE_X_START, timeline_rect.y + 4, 48, timeline_rect.h - 8};
             SDL_Rect title_rect = {block.x + 8, block.y + 8, block.w - 16, block.h - 16};
             char title[128];
 
+            if (!program) {
+                continue;
+            }
+            live_position = channel_live_position_precise(channel, app_start_ticks, now_ticks);
+            program_start_time = now_wall - (time_t) program_seek;
+            block_x = GUIDE_X_START + (int) (((double) (program_start_time - guide_view_start_time)) / 60.0 * pixels_per_minute);
+            block_w = (int) ((program->duration_seconds / 60.0) * pixels_per_minute);
+            block = (SDL_Rect){block_x, timeline_rect.y + 4, SDL_max(block_w, 48), timeline_rect.h - 8};
+            title_rect = (SDL_Rect){block.x + 8, block.y + 8, block.w - 16, block.h - 16};
+
             if (is_selected) {
                 draw_text_clipped(renderer, fonts->medium, channel->name, &sidebar, 20, row_rect.y + 12, COLOR_ACTIVE_TEXT);
                 {
@@ -601,7 +615,7 @@ void ui_render_guide(SDL_Renderer *renderer,
                 draw_cached_text(renderer, &cache->channels[channel_index].name_medium, 20, row_rect.y + 12);
                 draw_cached_text(renderer, &cache->channels[channel_index].number_medium, 176, row_rect.y + 12);
             }
-            draw_cached_text(renderer, &cache->channels[channel_index].file_small, 20, row_rect.y + 38);
+            draw_text_clipped(renderer, fonts->small, program->file_name, &sidebar, 20, row_rect.y + 38, COLOR_PALE_BLUE);
 
             SDL_RenderSetClipRect(renderer, &clip);
             draw_beveled_bar(renderer,
@@ -612,7 +626,7 @@ void ui_render_guide(SDL_Renderer *renderer,
                              is_selected ? COLOR_SELECTION_EDGE : COLOR_GLOSS,
                              COLOR_BORDER_DARK);
             fit_text_with_ellipsis(is_selected ? fonts->medium : fonts->small,
-                                   channel->program_title,
+                                   program->program_title,
                                    title_rect.w,
                                    title,
                                    sizeof(title));
@@ -676,17 +690,18 @@ int ui_cache_init(UiCache *cache, SDL_Renderer *renderer, const UiFonts *fonts,
 
         for (int i = 0; i < channels->count; ++i) {
             const Channel *channel = &channels->items[i];
+            const ProgramEntry *program = channel->program_count > 0 ? &channel->programs[0] : NULL;
             snprintf(buffer, sizeof(buffer), "%d", channel->number);
             if (text_texture_init(&cache->channels[i].name_medium, renderer, fonts->medium, channel->name, COLOR_TEXT_LIGHT) != 0 ||
                 text_texture_init(&cache->channels[i].number_medium, renderer, fonts->medium, buffer, COLOR_TEXT_LIGHT) != 0 ||
-                text_texture_init(&cache->channels[i].file_small, renderer, fonts->small, channel->file_name, COLOR_PALE_BLUE) != 0 ||
-                text_texture_init(&cache->channels[i].program_small_light, renderer, fonts->small, channel->program_title, COLOR_TEXT_LIGHT) != 0 ||
-                text_texture_init(&cache->channels[i].program_medium_dark, renderer, fonts->medium, channel->program_title, COLOR_TEXT_DARK) != 0) {
+                text_texture_init(&cache->channels[i].file_small, renderer, fonts->small, program ? program->file_name : "", COLOR_PALE_BLUE) != 0 ||
+                text_texture_init(&cache->channels[i].program_small_light, renderer, fonts->small, program ? program->program_title : "", COLOR_TEXT_LIGHT) != 0 ||
+                text_texture_init(&cache->channels[i].program_medium_dark, renderer, fonts->medium, program ? program->program_title : "", COLOR_TEXT_DARK) != 0) {
                 ui_cache_destroy(cache);
                 return -1;
             }
 
-            snprintf(buffer, sizeof(buffer), "%.0f min  -  %s", channel->duration_seconds / 60.0, channel->file_name);
+            snprintf(buffer, sizeof(buffer), "%.0f min  -  %s", program ? program->duration_seconds / 60.0 : 0.0, program ? program->file_name : "");
             if (text_texture_init(&cache->channels[i].detail_small_dark, renderer, fonts->small, buffer, COLOR_TEXT_DARK) != 0) {
                 ui_cache_destroy(cache);
                 return -1;