[FFmpeg-cvslog] Add support for aac streams in mp4/mov without extradata.

[Benjamin Larsson]

ffmpeg | branch: master | Benjamin Larsson <benjamin at southpole.se> | Mon Jun 27 23:39:12 2011 -0700| [dafaef2fe1e1af7c40adc1855547fd4cba9862a9] | committer: Alex Converse

Add support for aac streams in mp4/mov without extradata.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=dafaef2fe1e1af7c40adc1855547fd4cba9862a9
---

 libavcodec/aacdec.c |   42 ++++++++++++++++++++++++++++++++++++++++++
 libavformat/utils.c |   25 +++++++++++--------------
 2 files changed, 53 insertions(+), 14 deletions(-)

diff --git a/libavcodec/aacdec.c b/libavcodec/aacdec.c
index 26ce204..f26a4b7 100644
--- a/libavcodec/aacdec.c
+++ b/libavcodec/aacdec.c
@@ -530,6 +530,22 @@ static void reset_all_predictors(PredictorState *ps)
         reset_predict_state(&ps[i]);
 }
 
+static int sample_rate_idx (int rate)
+{
+         if (92017 <= rate) return 0;
+    else if (75132 <= rate) return 1;
+    else if (55426 <= rate) return 2;
+    else if (46009 <= rate) return 3;
+    else if (37566 <= rate) return 4;
+    else if (27713 <= rate) return 5;
+    else if (23004 <= rate) return 6;
+    else if (18783 <= rate) return 7;
+    else if (13856 <= rate) return 8;
+    else if (11502 <= rate) return 9;
+    else if (9391  <= rate) return 10;
+    else                    return 11;
+}
+
 static void reset_predictor_group(PredictorState *ps, int group_num)
 {
     int i;
@@ -552,10 +568,33 @@ static av_cold int aac_decode_init(AVCodecContext *avctx)
     ac->m4ac.sample_rate = avctx->sample_rate;
 
     if (avctx->extradata_size > 0) {
+        avctx->channels    = 0;
+        avctx->frame_size  = 0;
+        avctx->sample_rate = 0;
         if (decode_audio_specific_config(ac, ac->avctx, &ac->m4ac,
                                          avctx->extradata,
                                          avctx->extradata_size) < 0)
             return -1;
+    } else {
+        int sr, i;
+        enum ChannelPosition new_che_pos[4][MAX_ELEM_ID];
+
+        sr = sample_rate_idx(avctx->sample_rate);
+        ac->m4ac.sampling_index = sr;
+        ac->m4ac.channels = avctx->channels;
+
+        for (i = 0; i < FF_ARRAY_ELEMS(ff_mpeg4audio_channels); i++)
+            if (ff_mpeg4audio_channels[i] == avctx->channels)
+                break;
+        if (i == FF_ARRAY_ELEMS(ff_mpeg4audio_channels)) {
+            i = 0;
+        }
+        ac->m4ac.chan_config = i;
+
+        if (ac->m4ac.chan_config) {
+            set_default_channel_config(avctx, new_che_pos, ac->m4ac.chan_config);
+            output_configure(ac, ac->che_pos, new_che_pos, ac->m4ac.chan_config, OC_GLOBAL_HDR);
+        }
     }
 
     if (avctx->request_sample_fmt == AV_SAMPLE_FMT_FLT) {
@@ -2047,6 +2086,7 @@ static int parse_adts_frame_header(AACContext *ac, GetBitContext *gb)
             if (output_configure(ac, ac->che_pos, new_che_pos, hdr_info.chan_config, OC_TRIAL_FRAME))
                 return -7;
         } else if (ac->output_configured != OC_LOCKED) {
+            ac->m4ac.chan_config = 0;
             ac->output_configured = OC_NONE;
         }
         if (ac->output_configured != OC_LOCKED) {
@@ -2514,6 +2554,7 @@ AVCodec ff_aac_decoder = {
     .sample_fmts = (const enum AVSampleFormat[]) {
         AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE
     },
+    .capabilities = CODEC_CAP_CHANNEL_CONF,
     .channel_layouts = aac_channel_layout,
 };
 
@@ -2534,5 +2575,6 @@ AVCodec ff_aac_latm_decoder = {
     .sample_fmts = (const enum AVSampleFormat[]) {
         AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE
     },
+    .capabilities = CODEC_CAP_CHANNEL_CONF,
     .channel_layouts = aac_channel_layout,
 };
diff --git a/libavformat/utils.c b/libavformat/utils.c
index b12f785..776697b 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -2207,11 +2207,7 @@ int av_find_stream_info(AVFormatContext *ic)
     for(i=0;i<ic->nb_streams;i++) {
         AVCodec *codec;
         st = ic->streams[i];
-        if (st->codec->codec_id == CODEC_ID_AAC) {
-            st->codec->sample_rate = 0;
-            st->codec->frame_size = 0;
-            st->codec->channels = 0;
-        }
+
         if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO ||
             st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {
 /*            if(!st->time_base.num)
@@ -2229,13 +2225,6 @@ int av_find_stream_info(AVFormatContext *ic)
         assert(!st->codec->codec);
         codec = avcodec_find_decoder(st->codec->codec_id);
 
-        /* Force decoding of at least one frame of codec data
-         * this makes sure the codec initializes the channel configuration
-         * and does not trust the values from the container.
-         */
-        if (codec && codec->capabilities & CODEC_CAP_CHANNEL_CONF)
-            st->codec->channels = 0;
-
         /* Ensure that subtitle_header is properly set. */
         if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE
             && codec && !st->codec->codec)
@@ -2377,8 +2366,16 @@ int av_find_stream_info(AVFormatContext *ic)
         /* if still no information, we try to open the codec and to
            decompress the frame. We try to avoid that in most cases as
            it takes longer and uses more memory. For MPEG-4, we need to
-           decompress for QuickTime. */
-        if (!has_codec_parameters(st->codec) || !has_decode_delay_been_guessed(st))
+           decompress for QuickTime.
+
+           If CODEC_CAP_CHANNEL_CONF is set this will force decoding of at
+           least one frame of codec data, this makes sure the codec initializes
+           the channel configuration and does not only trust the values from the container.
+        */
+        if (!has_codec_parameters(st->codec) ||
+            !has_decode_delay_been_guessed(st) ||
+            (st->codec->codec &&
+             st->codec->codec->capabilities & CODEC_CAP_CHANNEL_CONF))
             try_decode_frame(st, pkt);
 
         st->codec_info_nb_frames++;