2 * H.264 MP4 to Annex B byte stream format filter
3 * Copyright (c) 2007 Benoit Fouet <benoit.fouet@free.fr>
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/intreadwrite.h"
25 typedef struct H264BSFContext {
31 static int alloc_and_copy(uint8_t **poutbuf, int *poutbuf_size,
32 const uint8_t *sps_pps, uint32_t sps_pps_size,
33 const uint8_t *in, uint32_t in_size) {
34 uint32_t offset = *poutbuf_size;
35 uint8_t nal_header_size = offset ? 3 : 4;
38 *poutbuf_size += sps_pps_size+in_size+nal_header_size;
39 tmp = av_realloc(*poutbuf, *poutbuf_size);
41 return AVERROR(ENOMEM);
44 memcpy(*poutbuf+offset, sps_pps, sps_pps_size);
45 memcpy(*poutbuf+sps_pps_size+nal_header_size+offset, in, in_size);
47 AV_WB32(*poutbuf+sps_pps_size, 1);
49 (*poutbuf+offset+sps_pps_size)[0] = (*poutbuf+offset+sps_pps_size)[1] = 0;
50 (*poutbuf+offset+sps_pps_size)[2] = 1;
56 static int h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc,
57 AVCodecContext *avctx, const char *args,
58 uint8_t **poutbuf, int *poutbuf_size,
59 const uint8_t *buf, int buf_size,
61 H264BSFContext *ctx = bsfc->priv_data;
64 uint32_t cumul_size = 0;
65 const uint8_t *buf_end = buf + buf_size;
66 int ret = AVERROR(EINVAL);
68 /* nothing to filter */
69 if (!avctx->extradata || avctx->extradata_size < 6) {
70 *poutbuf = (uint8_t*) buf;
71 *poutbuf_size = buf_size;
75 /* retrieve sps and pps NAL units from extradata */
76 if (!ctx->extradata_parsed) {
78 uint64_t total_size = 0;
79 uint8_t *out = NULL, unit_nb, sps_done = 0, sps_seen = 0, pps_seen = 0;
80 const uint8_t *extradata = avctx->extradata+4;
81 static const uint8_t nalu_header[4] = {0, 0, 0, 1};
83 /* retrieve length coded size */
84 ctx->length_size = (*extradata++ & 0x3) + 1;
85 if (ctx->length_size == 3)
86 return AVERROR(EINVAL);
88 /* retrieve sps and pps unit(s) */
89 unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
99 unit_size = AV_RB16(extradata);
100 total_size += unit_size+4;
101 if (total_size > INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE ||
102 extradata+2+unit_size > avctx->extradata+avctx->extradata_size) {
104 return AVERROR(EINVAL);
106 tmp = av_realloc(out, total_size + FF_INPUT_BUFFER_PADDING_SIZE);
109 return AVERROR(ENOMEM);
112 memcpy(out+total_size-unit_size-4, nalu_header, 4);
113 memcpy(out+total_size-unit_size, extradata+2, unit_size);
114 extradata += 2+unit_size;
116 if (!unit_nb && !sps_done++) {
117 unit_nb = *extradata++; /* number of pps unit(s) */
124 memset(out + total_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
127 av_log(avctx, AV_LOG_WARNING, "Warning: SPS NALU missing or invalid. The resulting stream may not play.\n");
129 av_log(avctx, AV_LOG_WARNING, "Warning: PPS NALU missing or invalid. The resulting stream may not play.\n");
131 av_free(avctx->extradata);
132 avctx->extradata = out;
133 avctx->extradata_size = total_size;
135 ctx->extradata_parsed = 1;
141 ret= AVERROR(EINVAL);
142 if (buf + ctx->length_size > buf_end)
145 if (ctx->length_size == 1) {
147 } else if (ctx->length_size == 2) {
148 nal_size = AV_RB16(buf);
150 nal_size = AV_RB32(buf);
152 buf += ctx->length_size;
153 unit_type = *buf & 0x1f;
155 if (buf + nal_size > buf_end || nal_size < 0)
158 /* prepend only to the first type 5 NAL unit of an IDR picture */
159 if (ctx->first_idr && unit_type == 5) {
160 if ((ret=alloc_and_copy(poutbuf, poutbuf_size,
161 avctx->extradata, avctx->extradata_size,
166 if ((ret=alloc_and_copy(poutbuf, poutbuf_size,
170 if (!ctx->first_idr && unit_type == 1)
175 cumul_size += nal_size + ctx->length_size;
176 } while (cumul_size < buf_size);
186 AVBitStreamFilter ff_h264_mp4toannexb_bsf = {
188 sizeof(H264BSFContext),
189 h264_mp4toannexb_filter,