[1/2] g722dec: Signal skipping the lower bits via AVOptions instead of bits_per_coded_sample

Message ID 1322936044-58230-1-git-send-email-martin@martin.st
State Committed
Commit 6fcbb0f553b8e45993e2746d3763adc2faec0781
Headers show

Commit Message

Martin Storsjö Dec. 3, 2011, 6:14 p.m.
This avoids using bits_per_coded_sample for this information.
bits_per_coded_sample should be 4 for this codec normally,
since two samples are encoded into one 8 bit codeword.

In principle, this might be info that needs to be passed from
a demuxer, and in that case, a private AVOption isn't the best
choice, but no such samples are available at the moment, so
that use case is purely theoretical at the moment.
---
 libavcodec/g722.h    |    2 ++
 libavcodec/g722dec.c |   32 +++++++++++++++++---------------
 2 files changed, 19 insertions(+), 15 deletions(-)

Comments

Justin Ruggles Dec. 3, 2011, 7:21 p.m. | #1
On 12/03/2011 01:14 PM, Martin Storsjö wrote:

> This avoids using bits_per_coded_sample for this information.
> bits_per_coded_sample should be 4 for this codec normally,
> since two samples are encoded into one 8 bit codeword.
> 
> In principle, this might be info that needs to be passed from
> a demuxer, and in that case, a private AVOption isn't the best
> choice, but no such samples are available at the moment, so
> that use case is purely theoretical at the moment.
> ---
>  libavcodec/g722.h    |    2 ++
>  libavcodec/g722dec.c |   32 +++++++++++++++++---------------
>  2 files changed, 19 insertions(+), 15 deletions(-)
> 
> diff --git a/libavcodec/g722.h b/libavcodec/g722.h
> index 69e7a86..eb3b9b8 100644
> --- a/libavcodec/g722.h
> +++ b/libavcodec/g722.h
> @@ -31,7 +31,9 @@
>  #define PREV_SAMPLES_BUF_SIZE 1024
>  
>  typedef struct {
> +    const AVClass *class;
>      AVFrame frame;
> +    int     bits_per_codeword;
>      int16_t prev_samples[PREV_SAMPLES_BUF_SIZE]; ///< memory of past decoded samples
>      int     prev_samples_pos;        ///< the number of values in prev_samples
>  
> diff --git a/libavcodec/g722dec.c b/libavcodec/g722dec.c
> index 652a1aa..50a224b 100644
> --- a/libavcodec/g722dec.c
> +++ b/libavcodec/g722dec.c
> @@ -37,6 +37,21 @@
>  #include "avcodec.h"
>  #include "get_bits.h"
>  #include "g722.h"
> +#include "libavutil/opt.h"
> +
> +#define OFFSET(x) offsetof(G722Context, x)
> +#define AD AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM
> +static const AVOption options[] = {
> +    { "bits_per_codeword", "Bits per G722 codeword", OFFSET(bits_per_codeword), AV_OPT_TYPE_FLAGS, { 8 }, 6, 8, AD },
> +    { NULL }
> +};
> +
> +static const AVClass g722_decoder_class = {
> +    .class_name = "g722 decoder",
> +    .item_name  = av_default_item_name,
> +    .option     = options,
> +    .version    = LIBAVUTIL_VERSION_INT,
> +};
>  
>  static av_cold int g722_decode_init(AVCodecContext * avctx)
>  {
> @@ -48,20 +63,6 @@ static av_cold int g722_decode_init(AVCodecContext * avctx)
>      }
>      avctx->sample_fmt = AV_SAMPLE_FMT_S16;
>  
> -    switch (avctx->bits_per_coded_sample) {
> -    case 8:
> -    case 7:
> -    case 6:
> -        break;
> -    default:
> -        av_log(avctx, AV_LOG_WARNING, "Unsupported bits_per_coded_sample [%d], "
> -                                      "assuming 8\n",
> -                                      avctx->bits_per_coded_sample);
> -    case 0:
> -        avctx->bits_per_coded_sample = 8;
> -        break;
> -    }
> -
>      c->band[0].scale_factor = 8;
>      c->band[1].scale_factor = 2;
>      c->prev_samples_pos = 22;
> @@ -89,7 +90,7 @@ static int g722_decode_frame(AVCodecContext *avctx, void *data,
>      G722Context *c = avctx->priv_data;
>      int16_t *out_buf;
>      int j, ret;
> -    const int skip = 8 - avctx->bits_per_coded_sample;
> +    const int skip = 8 - c->bits_per_codeword;
>      const int16_t *quantizer_table = low_inv_quants[skip];
>      GetBitContext gb;
>  
> @@ -149,4 +150,5 @@ AVCodec ff_adpcm_g722_decoder = {
>      .decode         = g722_decode_frame,
>      .capabilities   = CODEC_CAP_DR1,
>      .long_name      = NULL_IF_CONFIG_SMALL("G.722 ADPCM"),
> +    .priv_class     = &g722_decoder_class,
>  };


lgtm. thanks!

-Justin

Patch

diff --git a/libavcodec/g722.h b/libavcodec/g722.h
index 69e7a86..eb3b9b8 100644
--- a/libavcodec/g722.h
+++ b/libavcodec/g722.h
@@ -31,7 +31,9 @@ 
 #define PREV_SAMPLES_BUF_SIZE 1024
 
 typedef struct {
+    const AVClass *class;
     AVFrame frame;
+    int     bits_per_codeword;
     int16_t prev_samples[PREV_SAMPLES_BUF_SIZE]; ///< memory of past decoded samples
     int     prev_samples_pos;        ///< the number of values in prev_samples
 
diff --git a/libavcodec/g722dec.c b/libavcodec/g722dec.c
index 652a1aa..50a224b 100644
--- a/libavcodec/g722dec.c
+++ b/libavcodec/g722dec.c
@@ -37,6 +37,21 @@ 
 #include "avcodec.h"
 #include "get_bits.h"
 #include "g722.h"
+#include "libavutil/opt.h"
+
+#define OFFSET(x) offsetof(G722Context, x)
+#define AD AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM
+static const AVOption options[] = {
+    { "bits_per_codeword", "Bits per G722 codeword", OFFSET(bits_per_codeword), AV_OPT_TYPE_FLAGS, { 8 }, 6, 8, AD },
+    { NULL }
+};
+
+static const AVClass g722_decoder_class = {
+    .class_name = "g722 decoder",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
 
 static av_cold int g722_decode_init(AVCodecContext * avctx)
 {
@@ -48,20 +63,6 @@  static av_cold int g722_decode_init(AVCodecContext * avctx)
     }
     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
 
-    switch (avctx->bits_per_coded_sample) {
-    case 8:
-    case 7:
-    case 6:
-        break;
-    default:
-        av_log(avctx, AV_LOG_WARNING, "Unsupported bits_per_coded_sample [%d], "
-                                      "assuming 8\n",
-                                      avctx->bits_per_coded_sample);
-    case 0:
-        avctx->bits_per_coded_sample = 8;
-        break;
-    }
-
     c->band[0].scale_factor = 8;
     c->band[1].scale_factor = 2;
     c->prev_samples_pos = 22;
@@ -89,7 +90,7 @@  static int g722_decode_frame(AVCodecContext *avctx, void *data,
     G722Context *c = avctx->priv_data;
     int16_t *out_buf;
     int j, ret;
-    const int skip = 8 - avctx->bits_per_coded_sample;
+    const int skip = 8 - c->bits_per_codeword;
     const int16_t *quantizer_table = low_inv_quants[skip];
     GetBitContext gb;
 
@@ -149,4 +150,5 @@  AVCodec ff_adpcm_g722_decoder = {
     .decode         = g722_decode_frame,
     .capabilities   = CODEC_CAP_DR1,
     .long_name      = NULL_IF_CONFIG_SMALL("G.722 ADPCM"),
+    .priv_class     = &g722_decoder_class,
 };