avformat/matroskadec: Factor video parsing out of matroska_parse_tracks()

More exactly, factor codec-specific video parsing out of
matroska_parse_tracks(). This is intended to improve readability.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

1 files changed, 72 insertions, 48 deletions

diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index e9ad0c7e11..3348ce161e 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -2734,6 +2734,75 @@ static int mka_parse_audio_codec(MatroskaTrack *track, AVCodecParameters *par,
     return 0;
 }
 
+/* Performs the codec-specific part of parsing a video track. */
+static int mkv_parse_video_codec(MatroskaTrack *track, AVCodecParameters *par,
+                                 const MatroskaDemuxContext *matroska,
+                                 int *extradata_offset)
+{
+        if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC") &&
+            track->codec_priv.size >= 40) {
+            track->ms_compat    = 1;
+            par->bits_per_coded_sample = AV_RL16(track->codec_priv.data + 14);
+            par->codec_tag      = AV_RL32(track->codec_priv.data + 16);
+            par->codec_id       = ff_codec_get_id(ff_codec_bmp_tags,
+                                                  par->codec_tag);
+            if (!par->codec_id)
+                par->codec_id   = ff_codec_get_id(ff_codec_movvideo_tags,
+                                                  par->codec_tag);
+            *extradata_offset   = 40;
+            return 0;
+        } else if (!strcmp(track->codec_id, "V_QUICKTIME") &&
+                   track->codec_priv.size >= 21) {
+            enum AVCodecID codec_id;
+            uint32_t fourcc;
+            int ret = get_qt_codec(track, &fourcc, &codec_id);
+            if (ret < 0)
+                return ret;
+            if (codec_id == AV_CODEC_ID_NONE && AV_RL32(track->codec_priv.data+4) == AV_RL32("SMI ")) {
+                fourcc = MKTAG('S','V','Q','3');
+                codec_id = ff_codec_get_id(ff_codec_movvideo_tags, fourcc);
+            }
+            par->codec_id = codec_id;
+            if (codec_id == AV_CODEC_ID_NONE)
+                av_log(matroska->ctx, AV_LOG_ERROR,
+                       "mov FourCC not found %s.\n", av_fourcc2str(fourcc));
+            if (track->codec_priv.size >= 86) {
+        FFIOContext b;
+                unsigned bit_depth = AV_RB16(track->codec_priv.data + 82);
+                ffio_init_context(&b, track->codec_priv.data,
+                                  track->codec_priv.size,
+                                  0, NULL, NULL, NULL, NULL);
+                if (ff_get_qtpalette(codec_id, &b.pub, track->palette)) {
+                    bit_depth &= 0x1F;
+                    track->has_palette = 1;
+                }
+                par->bits_per_coded_sample = bit_depth;
+            }
+            par->codec_tag = fourcc;
+            return 0;
+        }
+
+    switch (par->codec_id) {
+    case AV_CODEC_ID_RV10:
+    case AV_CODEC_ID_RV20:
+    case AV_CODEC_ID_RV30:
+    case AV_CODEC_ID_RV40:
+        *extradata_offset = 26;
+        break;
+    case AV_CODEC_ID_PRORES:
+        if (track->codec_priv.size == 4)
+            par->codec_tag = AV_RL32(track->codec_priv.data);
+        break;
+    case AV_CODEC_ID_VP9:
+            /* we don't need any value stored in CodecPrivate.
+               make sure that it's not exported as extradata. */
+            track->codec_priv.size = 0;
+        break;
+    }
+
+    return 0;
+}
+
 static int matroska_parse_tracks(AVFormatContext *s)
 {
     MatroskaDemuxContext *matroska = s->priv_data;
@@ -2749,7 +2818,6 @@ static int matroska_parse_tracks(AVFormatContext *s)
         AVCodecParameters *par;
         int extradata_offset = 0;
         uint32_t fourcc = 0;
-        FFIOContext b;
         AVStream *st;
         FFStream *sti;
         char* key_id_base64 = NULL;
@@ -2934,55 +3002,11 @@ static int matroska_parse_tracks(AVFormatContext *s)
                 return ret;
             if (ret == SKIP_TRACK)
                 continue;
-        } else
-        if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC") &&
-            track->codec_priv.size >= 40) {
-            track->ms_compat    = 1;
-            par->bits_per_coded_sample = AV_RL16(track->codec_priv.data + 14);
-            par->codec_tag      = AV_RL32(track->codec_priv.data + 16);
-            par->codec_id       = ff_codec_get_id(ff_codec_bmp_tags,
-                                                  par->codec_tag);
-            if (!par->codec_id)
-                par->codec_id   = ff_codec_get_id(ff_codec_movvideo_tags,
-                                                  par->codec_tag);
-            extradata_offset    = 40;
-        } else if (!strcmp(track->codec_id, "V_QUICKTIME") &&
-                   track->codec_priv.size >= 21) {
-            uint32_t fourcc;
-            int ret = get_qt_codec(track, &fourcc, &codec_id);
+        } else if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
+            ret = mkv_parse_video_codec(track, par, matroska,
+                                        &extradata_offset);
             if (ret < 0)
                 return ret;
-            if (codec_id == AV_CODEC_ID_NONE && AV_RL32(track->codec_priv.data+4) == AV_RL32("SMI ")) {
-                fourcc = MKTAG('S','V','Q','3');
-                codec_id = ff_codec_get_id(ff_codec_movvideo_tags, fourcc);
-            }
-            par->codec_id = codec_id;
-            if (codec_id == AV_CODEC_ID_NONE)
-                av_log(matroska->ctx, AV_LOG_ERROR,
-                       "mov FourCC not found %s.\n", av_fourcc2str(fourcc));
-            if (track->codec_priv.size >= 86) {
-                unsigned bit_depth = AV_RB16(track->codec_priv.data + 82);
-                ffio_init_context(&b, track->codec_priv.data,
-                                  track->codec_priv.size,
-                                  0, NULL, NULL, NULL, NULL);
-                if (ff_get_qtpalette(codec_id, &b.pub, track->palette)) {
-                    bit_depth &= 0x1F;
-                    track->has_palette = 1;
-                }
-                par->bits_per_coded_sample = bit_depth;
-            }
-            par->codec_tag = fourcc;
-        } else if (codec_id == AV_CODEC_ID_RV10 ||
-                   codec_id == AV_CODEC_ID_RV20 ||
-                   codec_id == AV_CODEC_ID_RV30 ||
-                   codec_id == AV_CODEC_ID_RV40) {
-            extradata_offset = 26;
-        } else if (codec_id == AV_CODEC_ID_PRORES && track->codec_priv.size == 4) {
-            par->codec_tag = AV_RL32(track->codec_priv.data);
-        } else if (codec_id == AV_CODEC_ID_VP9) {
-            /* we don't need any value stored in CodecPrivate.
-               make sure that it's not exported as extradata. */
-            track->codec_priv.size = 0;
         } else if (codec_id == AV_CODEC_ID_ARIB_CAPTION && track->codec_priv.size == 3) {
             int component_tag = track->codec_priv.data[0];
             int data_component_id = AV_RB16(track->codec_priv.data + 1);