doc

doc/TXTH.md

@@ -303,11 +303,13 @@ id_check = (value)
 ```
 
 #### NUMBER OF CHANNELS [REQUIRED]
+How many audio channels the file has, typically 2 (stereo).
 ```
 channels = (value)
 ```
 
-#### MUSIC FREQUENCY [REQUIRED]
+#### AUDIO FREQUENCY [REQUIRED]
+Number of samples per second, typically 48000/44100/32000/24000/22050/11025.
 ```
 sample_rate = (value)
 ```

src/coding/ffmpeg_decoder.c

@@ -432,11 +432,16 @@ fail:
 
 /* FFmpeg internals (roughly) for reference:
  * 
+ *   // metadata info first extracted 
  *   AVFormatContext                    // base info extracted from input file
  *     AVStream                         // substreams
  *       AVCodecParameters              // codec id, channels, format, ...
  *   
- *   AVCodecContext                     // sample rate and general info
+ *   // codec info passed to 'decode' functions
+ *   AVCodecContext                     // codec's sample rate, priv data and general info
+ *   AVPacket                           // encoded data (1 or N frames) passed to decoder
+ *   AVFrame                            // decoded data (audio samples + channels + etc) received from decoder
+ *                                      //  (bufs are internally managed)
  * 
  * - open avformat to get all possible format info (needs file or custom IO)
  * - open avcodec based on target stream + codec info from avformat
@@ -444,8 +449,13 @@ fail:
  *   - read next frame into packet via avformat
  *   - decode packet via avcodec
  *   - handle samples
-*/
-
+ * 
+ * In FFmpeg, each "avformat" defines an struct with format info/config and read_probe (detection) + read_header
+ * (setup format/codec params) + read_packet (demux single frame) functions. Meanwhile "avcodec" defines an struct
+ * with config and decode_init/close (setup, may use first block's data to init itself or some extradata from
+ * avformat) + decode_frame (loads AVFrame from AVPacket) + decode_flush (reset state).
+ * Codec/demuxer contexts aren't alloc'd manually and instead they declare priv data size.
+ */
 static int init_ffmpeg_config(ffmpeg_codec_data* data, int target_subsong, int reset) {
     int errcode = 0;
 

src/layout/layered.c

@@ -35,7 +35,7 @@ void render_vgmstream_layered(sbuf_t* sdst, VGMSTREAM* vgmstream) {
             samples_to_do = sdst->samples - sdst->filled;
 
         if (samples_to_do <= 0) { /* when decoding more than num_samples */
-            VGM_LOG_ONCE("LAYERED: wrong samples_to_do\n"); 
+            VGM_LOG_ONCE("LAYERED: wrong %i samples_to_do (%i filled vs %i samples)\n", samples_to_do, sdst->filled, sdst->samples); 
             goto decode_fail;
         }
 

src/meta/bik.c

@@ -6,16 +6,13 @@ static bool bink_get_info(STREAMFILE* sf, int target_subsong, int* p_total_subso
 
 /* BINK 1/2 - RAD Game Tools movies (audio/video format) */
 VGMSTREAM* init_vgmstream_bik(STREAMFILE* sf) {
-    VGMSTREAM * vgmstream = NULL;
-    int channels = 0, loop_flag = 0, sample_rate = 0, num_samples = 0;
-    int total_subsongs = 0, target_subsong = sf->stream_index;
-    size_t stream_size;
+    VGMSTREAM* vgmstream = NULL;
 
     /* checks */
     /* bink1/2 header, followed by version-char (audio is the same) */
     if ((read_u32be(0x00,sf) & 0xffffff00) != get_id32be("BIK\0") &&
         (read_u32be(0x00,sf) & 0xffffff00) != get_id32be("KB2\0"))
-        goto fail;
+        return NULL;
 
     /* .bik/bk2: standard
     *  .bik2: older?
@@ -25,7 +22,13 @@ VGMSTREAM* init_vgmstream_bik(STREAMFILE* sf) {
      * .vid: Etrange Libellules games [Alice in Wonderland (PC)] 
      * .bika: fake extension for demuxed audio */
     if (!check_extensions(sf,"bik,bk2,bik2,ps3,xmv,xen,vid,bika"))
-        goto fail;
+        return NULL;
+
+    /* this typically handles regular or demuxed videos, but .bik with a 4x4 video made for audio do exist [Viva Piñata (DS)] */
+
+    int channels = 0, loop_flag = 0, sample_rate = 0, num_samples = 0;
+    int total_subsongs = 0, target_subsong = sf->stream_index;
+    size_t stream_size;
 
     /* find target stream info and samples */
     if (!bink_get_info(sf, target_subsong, &total_subsongs, &stream_size, &channels, &sample_rate, &num_samples))