[libav-devel] [PATCH 28/57] libgsm: implement new audio decoding API

Justin Ruggles justin.ruggles at gmail.com
Sat Nov 26 23:06:39 CET 2011


---
 libavcodec/libgsm.c |   58 +++++++++++++++++++++++++++++++++++---------------
 1 files changed, 40 insertions(+), 18 deletions(-)

diff --git a/libavcodec/libgsm.c b/libavcodec/libgsm.c
index c02594d..22629c6 100644
--- a/libavcodec/libgsm.c
+++ b/libavcodec/libgsm.c
@@ -124,7 +124,14 @@ AVCodec ff_libgsm_ms_encoder = {
     .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"),
 };
 
+typedef struct LibGSMDecodeContext {
+    AVFrame frame;
+    struct gsm_state *state;
+} LibGSMDecodeContext;
+
 static av_cold int libgsm_decode_init(AVCodecContext *avctx) {
+    LibGSMDecodeContext *s = avctx->priv_data;
+
     if (avctx->channels > 1) {
         av_log(avctx, AV_LOG_ERROR, "Mono required for GSM, got %d channels\n",
                avctx->channels);
@@ -139,7 +146,7 @@ static av_cold int libgsm_decode_init(AVCodecContext *avctx) {
 
     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
 
-    avctx->priv_data = gsm_create();
+    s->state = gsm_create();
 
     switch(avctx->codec_id) {
     case CODEC_ID_GSM:
@@ -154,59 +161,72 @@ static av_cold int libgsm_decode_init(AVCodecContext *avctx) {
         }
     }
 
+    avcodec_get_frame_defaults(&s->frame);
+    avctx->coded_frame = &s->frame;
+
     return 0;
 }
 
 static av_cold int libgsm_decode_close(AVCodecContext *avctx) {
-    gsm_destroy(avctx->priv_data);
-    avctx->priv_data = NULL;
+    LibGSMDecodeContext *s = avctx->priv_data;
+
+    gsm_destroy(s->state);
+    s->state = NULL;
     return 0;
 }
 
-static int libgsm_decode_frame(AVCodecContext *avctx,
-                               void *data, int *data_size,
-                               AVPacket *avpkt) {
+static int libgsm_decode_frame(AVCodecContext *avctx, void *data,
+                               int *got_frame_ptr, AVPacket *avpkt)
+{
     int i, ret;
-    struct gsm_state *s = avctx->priv_data;
+    LibGSMDecodeContext *s = avctx->priv_data;
     uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;
-    int16_t *samples = data;
-    int out_size = avctx->frame_size * av_get_bytes_per_sample(avctx->sample_fmt);
-
-    if (*data_size < out_size) {
-        av_log(avctx, AV_LOG_ERROR, "Output buffer is too small\n");
-        return AVERROR(EINVAL);
-    }
+    int16_t *samples;
 
     if (buf_size < avctx->block_align) {
         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
         return AVERROR_INVALIDDATA;
     }
 
+    /* get output buffer */
+    s->frame.nb_samples = avctx->frame_size;
+    if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+        return ret;
+    }
+    samples = (int16_t *)s->frame.data[0];
+
     for (i = 0; i < avctx->frame_size / GSM_FRAME_SIZE; i++) {
-        if ((ret = gsm_decode(s, buf, samples)) < 0)
+        if ((ret = gsm_decode(s->state, buf, samples)) < 0)
             return -1;
         buf     += GSM_BLOCK_SIZE;
         samples += GSM_FRAME_SIZE;
     }
 
-    *data_size = out_size;
+    *got_frame_ptr   = 1;
+    *(AVFrame *)data = s->frame;
+
     return avctx->block_align;
 }
 
 static void libgsm_flush(AVCodecContext *avctx) {
-    gsm_destroy(avctx->priv_data);
-    avctx->priv_data = gsm_create();
+    LibGSMDecodeContext *s = avctx->priv_data;
+
+    gsm_destroy(s->state);
+    s->state = gsm_create();
 }
 
 AVCodec ff_libgsm_decoder = {
     .name           = "libgsm",
     .type           = AVMEDIA_TYPE_AUDIO,
     .id             = CODEC_ID_GSM,
+    .priv_data_size = sizeof(LibGSMDecodeContext),
     .init           = libgsm_decode_init,
     .close          = libgsm_decode_close,
     .decode         = libgsm_decode_frame,
     .flush          = libgsm_flush,
+    .capabilities   = CODEC_CAP_DR1,
     .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM"),
 };
 
@@ -214,9 +234,11 @@ AVCodec ff_libgsm_ms_decoder = {
     .name           = "libgsm_ms",
     .type           = AVMEDIA_TYPE_AUDIO,
     .id             = CODEC_ID_GSM_MS,
+    .priv_data_size = sizeof(LibGSMDecodeContext),
     .init           = libgsm_decode_init,
     .close          = libgsm_decode_close,
     .decode         = libgsm_decode_frame,
     .flush          = libgsm_flush,
+    .capabilities   = CODEC_CAP_DR1,
     .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"),
 };
-- 
1.7.1



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