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
24 #include "libavutil/intreadwrite.h"
25 #include "libavutil/mem.h"
28 typedef struct H264BSFContext {
34 static int alloc_and_copy(uint8_t **poutbuf, int *poutbuf_size,
35 const uint8_t *sps_pps, uint32_t sps_pps_size,
36 const uint8_t *in, uint32_t in_size)
38 uint32_t offset = *poutbuf_size;
39 uint8_t nal_header_size = offset ? 3 : 4;
42 *poutbuf_size += sps_pps_size + in_size + nal_header_size;
43 tmp = av_realloc(*poutbuf, *poutbuf_size);
45 return AVERROR(ENOMEM);
48 memcpy(*poutbuf + offset, sps_pps, sps_pps_size);
49 memcpy(*poutbuf + sps_pps_size + nal_header_size + offset, in, in_size);
51 AV_WB32(*poutbuf + sps_pps_size, 1);
53 (*poutbuf + offset + sps_pps_size)[0] =
54 (*poutbuf + offset + sps_pps_size)[1] = 0;
55 (*poutbuf + offset + sps_pps_size)[2] = 1;
61 static int h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc,
62 AVCodecContext *avctx, const char *args,
63 uint8_t **poutbuf, int *poutbuf_size,
64 const uint8_t *buf, int buf_size,
67 H264BSFContext *ctx = bsfc->priv_data;
71 uint32_t cumul_size = 0;
72 const uint8_t *buf_end = buf + buf_size;
73 int ret = AVERROR(EINVAL);
75 /* nothing to filter */
76 if (!avctx->extradata || avctx->extradata_size < 6) {
77 *poutbuf = (uint8_t *)buf;
78 *poutbuf_size = buf_size;
82 /* retrieve sps and pps NAL units from extradata */
83 if (!ctx->extradata_parsed) {
85 uint64_t total_size = 0;
86 uint8_t *out = NULL, unit_nb, sps_done = 0,
87 sps_seen = 0, pps_seen = 0;
88 const uint8_t *extradata = avctx->extradata + 4;
89 static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
91 /* retrieve length coded size */
92 ctx->length_size = (*extradata++ & 0x3) + 1;
94 /* retrieve sps and pps unit(s) */
95 unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
105 unit_size = AV_RB16(extradata);
106 total_size += unit_size + 4;
107 if (total_size > INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE ||
108 extradata + 2 + unit_size > avctx->extradata +
109 avctx->extradata_size) {
111 return AVERROR(EINVAL);
113 tmp = av_realloc(out, total_size + FF_INPUT_BUFFER_PADDING_SIZE);
116 return AVERROR(ENOMEM);
119 memcpy(out + total_size - unit_size - 4, nalu_header, 4);
120 memcpy(out + total_size - unit_size, extradata + 2, unit_size);
121 extradata += 2 + unit_size;
123 if (!unit_nb && !sps_done++) {
124 unit_nb = *extradata++; /* number of pps unit(s) */
131 memset(out + total_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
134 av_log(avctx, AV_LOG_WARNING,
135 "Warning: SPS NALU missing or invalid. "
136 "The resulting stream may not play.\n");
139 av_log(avctx, AV_LOG_WARNING,
140 "Warning: PPS NALU missing or invalid. "
141 "The resulting stream may not play.\n");
143 av_free(avctx->extradata);
144 avctx->extradata = out;
145 avctx->extradata_size = total_size;
147 ctx->extradata_parsed = 1;
153 ret= AVERROR(EINVAL);
154 if (buf + ctx->length_size > buf_end)
157 for (nal_size = 0, i = 0; i<ctx->length_size; i++)
158 nal_size = (nal_size << 8) | buf[i];
160 buf += ctx->length_size;
161 unit_type = *buf & 0x1f;
163 if (buf + nal_size > buf_end || nal_size < 0)
166 /* prepend only to the first type 5 NAL unit of an IDR picture */
167 if (ctx->first_idr && unit_type == 5) {
168 if ((ret=alloc_and_copy(poutbuf, poutbuf_size,
169 avctx->extradata, avctx->extradata_size,
174 if ((ret=alloc_and_copy(poutbuf, poutbuf_size,
175 NULL, 0, buf, nal_size)) < 0)
177 if (!ctx->first_idr && unit_type == 1)
182 cumul_size += nal_size + ctx->length_size;
183 } while (cumul_size < buf_size);
193 AVBitStreamFilter ff_h264_mp4toannexb_bsf = {
195 sizeof(H264BSFContext),
196 h264_mp4toannexb_filter,