[FFmpeg-cvslog] h264: decouple extradata parsing from the decoder
Anton Khirnov
git at videolan.org
Sun Jun 19 12:22:24 CEST 2016
ffmpeg | branch: master | Anton Khirnov <anton at khirnov.net> | Tue Mar 29 04:09:14 2016 +0200| [98c97994c5b90bdae02accb155eeceeb5224b8ef] | committer: Anton Khirnov
h264: decouple extradata parsing from the decoder
This will allow decoupling the parser from the decoder.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=98c97994c5b90bdae02accb155eeceeb5224b8ef
---
libavcodec/h264.c | 133 ++----------------------------------------
libavcodec/h264.h | 1 -
libavcodec/h264_parse.c | 144 ++++++++++++++++++++++++++++++++++++++++++++++
libavcodec/h264_parse.h | 5 ++
libavcodec/h264_parser.c | 6 +-
5 files changed, 159 insertions(+), 130 deletions(-)
diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index 060feb9..7db97ef 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -278,117 +278,6 @@ fail:
return AVERROR(ENOMEM); // ff_h264_free_tables will clean up for us
}
-static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size,
- int parse_extradata);
-
-/* There are (invalid) samples in the wild with mp4-style extradata, where the
- * parameter sets are stored unescaped (i.e. as RBSP).
- * This function catches the parameter set decoding failure and tries again
- * after escaping it */
-static int decode_extradata_ps_mp4(H264Context *h, const uint8_t *buf, int buf_size)
-{
- int ret;
-
- ret = decode_nal_units(h, buf, buf_size, 1);
- if (ret < 0 && !(h->avctx->err_recognition & AV_EF_EXPLODE)) {
- GetByteContext gbc;
- PutByteContext pbc;
- uint8_t *escaped_buf;
- int escaped_buf_size;
-
- av_log(h->avctx, AV_LOG_WARNING,
- "SPS decoding failure, trying again after escaping the NAL\n");
-
- if (buf_size / 2 >= (INT16_MAX - AV_INPUT_BUFFER_PADDING_SIZE) / 3)
- return AVERROR(ERANGE);
- escaped_buf_size = buf_size * 3 / 2 + AV_INPUT_BUFFER_PADDING_SIZE;
- escaped_buf = av_mallocz(escaped_buf_size);
- if (!escaped_buf)
- return AVERROR(ENOMEM);
-
- bytestream2_init(&gbc, buf, buf_size);
- bytestream2_init_writer(&pbc, escaped_buf, escaped_buf_size);
-
- while (bytestream2_get_bytes_left(&gbc)) {
- if (bytestream2_get_bytes_left(&gbc) >= 3 &&
- bytestream2_peek_be24(&gbc) <= 3) {
- bytestream2_put_be24(&pbc, 3);
- bytestream2_skip(&gbc, 2);
- } else
- bytestream2_put_byte(&pbc, bytestream2_get_byte(&gbc));
- }
-
- escaped_buf_size = bytestream2_tell_p(&pbc);
- AV_WB16(escaped_buf, escaped_buf_size - 2);
-
- ret = decode_nal_units(h, escaped_buf, escaped_buf_size, 1);
- av_freep(&escaped_buf);
- if (ret < 0)
- return ret;
- }
-
- return 0;
-}
-
-int ff_h264_decode_extradata(H264Context *h)
-{
- AVCodecContext *avctx = h->avctx;
- int ret;
-
- if (avctx->extradata[0] == 1) {
- int i, cnt, nalsize;
- unsigned char *p = avctx->extradata;
-
- h->is_avc = 1;
-
- if (avctx->extradata_size < 7) {
- av_log(avctx, AV_LOG_ERROR,
- "avcC %d too short\n", avctx->extradata_size);
- return AVERROR_INVALIDDATA;
- }
- /* sps and pps in the avcC always have length coded with 2 bytes,
- * so put a fake nal_length_size = 2 while parsing them */
- h->nal_length_size = 2;
- // Decode sps from avcC
- cnt = *(p + 5) & 0x1f; // Number of sps
- p += 6;
- for (i = 0; i < cnt; i++) {
- nalsize = AV_RB16(p) + 2;
- if (p - avctx->extradata + nalsize > avctx->extradata_size)
- return AVERROR_INVALIDDATA;
- ret = decode_extradata_ps_mp4(h, p, nalsize);
- if (ret < 0) {
- av_log(avctx, AV_LOG_ERROR,
- "Decoding sps %d from avcC failed\n", i);
- return ret;
- }
- p += nalsize;
- }
- // Decode pps from avcC
- cnt = *(p++); // Number of pps
- for (i = 0; i < cnt; i++) {
- nalsize = AV_RB16(p) + 2;
- if (p - avctx->extradata + nalsize > avctx->extradata_size)
- return AVERROR_INVALIDDATA;
- ret = decode_extradata_ps_mp4(h, p, nalsize);
- if (ret < 0) {
- av_log(avctx, AV_LOG_ERROR,
- "Decoding pps %d from avcC failed\n", i);
- return ret;
- }
- p += nalsize;
- }
- // Store right nal length size that will be used to parse all other nals
- h->nal_length_size = (avctx->extradata[4] & 0x03) + 1;
- } else {
- h->is_avc = 0;
- ret = decode_nal_units(h, avctx->extradata, avctx->extradata_size, 1);
- if (ret < 0)
- return ret;
- }
- return 0;
-}
-
static int h264_init_context(AVCodecContext *avctx, H264Context *h)
{
int i;
@@ -462,7 +351,9 @@ av_cold int ff_h264_decode_init(AVCodecContext *avctx)
}
if (avctx->extradata_size > 0 && avctx->extradata) {
- ret = ff_h264_decode_extradata(h);
+ ret = ff_h264_decode_extradata(avctx->extradata, avctx->extradata_size,
+ &h->ps, &h->is_avc, &h->nal_length_size,
+ avctx->err_recognition, avctx);
if (ret < 0) {
ff_h264_free_context(h);
return ret;
@@ -919,8 +810,7 @@ static int get_last_needed_nal(H264Context *h)
return nals_needed;
}
-static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size,
- int parse_extradata)
+static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size)
{
AVCodecContext *const avctx = h->avctx;
unsigned context_count = 0;
@@ -956,19 +846,6 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size,
continue;
again:
- /* Ignore every NAL unit type except PPS and SPS during extradata
- * parsing. Decoding slices is not possible in codec init
- * with frame-mt */
- if (parse_extradata && HAVE_THREADS &&
- (h->avctx->active_thread_type & FF_THREAD_FRAME) &&
- (nal->type != NAL_PPS && nal->type != NAL_SPS)) {
- if (nal->type < NAL_AUD || nal->type > NAL_AUXILIARY_SLICE)
- av_log(avctx, AV_LOG_INFO,
- "Ignoring NAL unit %d during extradata parsing\n",
- nal->type);
- nal->type = NAL_FF_IGNORE;
- }
-
// FIXME these should stop being context-global variables
h->nal_ref_idc = nal->ref_idc;
h->nal_unit_type = nal->type;
@@ -1183,7 +1060,7 @@ out:
return buf_index;
}
- buf_index = decode_nal_units(h, buf, buf_size, 0);
+ buf_index = decode_nal_units(h, buf, buf_size);
if (buf_index < 0)
return AVERROR_INVALIDDATA;
diff --git a/libavcodec/h264.h b/libavcodec/h264.h
index a7e926b..4590bdb 100644
--- a/libavcodec/h264.h
+++ b/libavcodec/h264.h
@@ -706,7 +706,6 @@ int ff_h264_decode_ref_pic_marking(H264Context *h, GetBitContext *gb,
int ff_generate_sliding_window_mmcos(H264Context *h, int first_slice);
void ff_h264_hl_decode_mb(const H264Context *h, H264SliceContext *sl);
-int ff_h264_decode_extradata(H264Context *h);
int ff_h264_decode_init(AVCodecContext *avctx);
void ff_h264_decode_init_vlc(void);
diff --git a/libavcodec/h264_parse.c b/libavcodec/h264_parse.c
index 4ab0fde..1fc8f41 100644
--- a/libavcodec/h264_parse.c
+++ b/libavcodec/h264_parse.c
@@ -16,6 +16,7 @@
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#include "bytestream.h"
#include "get_bits.h"
#include "golomb.h"
#include "h264.h"
@@ -305,3 +306,146 @@ int ff_h264_init_poc(int pic_field_poc[2], int *pic_poc,
return 0;
}
+
+static int decode_extradata_ps(const uint8_t *data, int size, H264ParamSets *ps,
+ int is_avc, void *logctx)
+{
+ H2645Packet pkt = { 0 };
+ int i, ret = 0;
+
+ ret = ff_h2645_packet_split(&pkt, data, size, logctx, is_avc, 2, AV_CODEC_ID_H264);
+ if (ret < 0)
+ goto fail;
+
+ for (i = 0; i < pkt.nb_nals; i++) {
+ H2645NAL *nal = &pkt.nals[i];
+ switch (nal->type) {
+ case NAL_SPS:
+ ret = ff_h264_decode_seq_parameter_set(&nal->gb, logctx, ps);
+ if (ret < 0)
+ goto fail;
+ break;
+ case NAL_PPS:
+ ret = ff_h264_decode_picture_parameter_set(&nal->gb, logctx, ps,
+ nal->size_bits);
+ if (ret < 0)
+ goto fail;
+ break;
+ default:
+ av_log(logctx, AV_LOG_VERBOSE, "Ignoring NAL type %d in extradata\n",
+ nal->type);
+ break;
+ }
+ }
+
+fail:
+ ff_h2645_packet_uninit(&pkt);
+ return ret;
+}
+
+/* There are (invalid) samples in the wild with mp4-style extradata, where the
+ * parameter sets are stored unescaped (i.e. as RBSP).
+ * This function catches the parameter set decoding failure and tries again
+ * after escaping it */
+static int decode_extradata_ps_mp4(const uint8_t *buf, int buf_size, H264ParamSets *ps,
+ int err_recognition, void *logctx)
+{
+ int ret;
+
+ ret = decode_extradata_ps(buf, buf_size, ps, 1, logctx);
+ if (ret < 0 && !(err_recognition & AV_EF_EXPLODE)) {
+ GetByteContext gbc;
+ PutByteContext pbc;
+ uint8_t *escaped_buf;
+ int escaped_buf_size;
+
+ av_log(logctx, AV_LOG_WARNING,
+ "SPS decoding failure, trying again after escaping the NAL\n");
+
+ if (buf_size / 2 >= (INT16_MAX - AV_INPUT_BUFFER_PADDING_SIZE) / 3)
+ return AVERROR(ERANGE);
+ escaped_buf_size = buf_size * 3 / 2 + AV_INPUT_BUFFER_PADDING_SIZE;
+ escaped_buf = av_mallocz(escaped_buf_size);
+ if (!escaped_buf)
+ return AVERROR(ENOMEM);
+
+ bytestream2_init(&gbc, buf, buf_size);
+ bytestream2_init_writer(&pbc, escaped_buf, escaped_buf_size);
+
+ while (bytestream2_get_bytes_left(&gbc)) {
+ if (bytestream2_get_bytes_left(&gbc) >= 3 &&
+ bytestream2_peek_be24(&gbc) <= 3) {
+ bytestream2_put_be24(&pbc, 3);
+ bytestream2_skip(&gbc, 2);
+ } else
+ bytestream2_put_byte(&pbc, bytestream2_get_byte(&gbc));
+ }
+
+ escaped_buf_size = bytestream2_tell_p(&pbc);
+ AV_WB16(escaped_buf, escaped_buf_size - 2);
+
+ ret = decode_extradata_ps(escaped_buf, escaped_buf_size, ps, 1, logctx);
+ av_freep(&escaped_buf);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+int ff_h264_decode_extradata(const uint8_t *data, int size, H264ParamSets *ps,
+ int *is_avc, int *nal_length_size,
+ int err_recognition, void *logctx)
+{
+ int ret;
+
+ if (data[0] == 1) {
+ int i, cnt, nalsize;
+ const uint8_t *p = data;
+
+ *is_avc = 1;
+
+ if (size < 7) {
+ av_log(logctx, AV_LOG_ERROR, "avcC %d too short\n", size);
+ return AVERROR_INVALIDDATA;
+ }
+
+ // Decode sps from avcC
+ cnt = *(p + 5) & 0x1f; // Number of sps
+ p += 6;
+ for (i = 0; i < cnt; i++) {
+ nalsize = AV_RB16(p) + 2;
+ if (p - data + nalsize > size)
+ return AVERROR_INVALIDDATA;
+ ret = decode_extradata_ps_mp4(p, nalsize, ps, err_recognition, logctx);
+ if (ret < 0) {
+ av_log(logctx, AV_LOG_ERROR,
+ "Decoding sps %d from avcC failed\n", i);
+ return ret;
+ }
+ p += nalsize;
+ }
+ // Decode pps from avcC
+ cnt = *(p++); // Number of pps
+ for (i = 0; i < cnt; i++) {
+ nalsize = AV_RB16(p) + 2;
+ if (p - data + nalsize > size)
+ return AVERROR_INVALIDDATA;
+ ret = decode_extradata_ps_mp4(p, nalsize, ps, err_recognition, logctx);
+ if (ret < 0) {
+ av_log(logctx, AV_LOG_ERROR,
+ "Decoding pps %d from avcC failed\n", i);
+ return ret;
+ }
+ p += nalsize;
+ }
+ // Store right nal length size that will be used to parse all other nals
+ *nal_length_size = (data[4] & 0x03) + 1;
+ } else {
+ *is_avc = 0;
+ ret = decode_extradata_ps(data, size, ps, 0, logctx);
+ if (ret < 0)
+ return ret;
+ }
+ return 0;
+}
diff --git a/libavcodec/h264_parse.h b/libavcodec/h264_parse.h
index c47b420..617ee4e 100644
--- a/libavcodec/h264_parse.h
+++ b/libavcodec/h264_parse.h
@@ -54,6 +54,7 @@ typedef struct H264POCContext {
struct SPS;
struct PPS;
+struct H264ParamSets;
int ff_h264_pred_weight_table(GetBitContext *gb, const struct SPS *sps,
const int *ref_count, int slice_type_nos,
@@ -82,4 +83,8 @@ int ff_h264_init_poc(int pic_field_poc[2], int *pic_poc,
const struct SPS *sps, H264POCContext *poc,
int picture_structure, int nal_ref_idc);
+int ff_h264_decode_extradata(const uint8_t *data, int size, struct H264ParamSets *ps,
+ int *is_avc, int *nal_length_size,
+ int err_recognition, void *logctx);
+
#endif /* AVCODEC_H264_PARSE_H */
diff --git a/libavcodec/h264_parser.c b/libavcodec/h264_parser.c
index 7c674b8..9a6464c 100644
--- a/libavcodec/h264_parser.c
+++ b/libavcodec/h264_parser.c
@@ -50,6 +50,8 @@ typedef struct H264ParseContext {
H264DSPContext h264dsp;
H264POCContext poc;
H264SEIContext sei;
+ int is_avc;
+ int nal_length_size;
int got_first;
} H264ParseContext;
@@ -500,7 +502,9 @@ static int h264_parse(AVCodecParserContext *s,
// NB: estimate_timings_from_pts behaves exactly like this.
if (!avctx->has_b_frames)
h->low_delay = 1;
- ff_h264_decode_extradata(h);
+ ff_h264_decode_extradata(avctx->extradata, avctx->extradata_size,
+ &p->ps, &p->is_avc, &p->nal_length_size,
+ avctx->err_recognition, avctx);
}
}
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