This changes the default behaviour of ffmpeg where content-type headers on an input gives an absolut probe score (of 75) to instead give a bonus score (of 30). This gives the probe a better chance to arrive at the correct format by (hopefully) giving a large enough bonus to push edge cases in the right direction (MPEG-PS vs MP3, I am looking at you) while also not adversly punishing clearer cases (raw ADTS marked as "audio/mpeg" for example). This patch was regression tested against 20 million recent podcast submissions (after content-type propagation was added to original-storage), and 50k Juno vodcasts submissions (dito). No adverse effects observed (but the bonus may still need tweaking if other edge cases are detected in production).
Unified · Split
| @@ -459,7 +459,7 @@ typedef struct AVProbeData { · 458 unmodified lines | ||
| 459 | 459 | #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1) |
| 460 | 460 | |
| 461 | 461 | #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension |
| 462 | −#define AVPROBE_SCORE_MIME 75 ///< score for file mime type | |
| 462 | +#define AVPROBE_SCORE_MIME_BONUS 30 ///< score added for matching mime type | |
| 463 | 463 | #define AVPROBE_SCORE_MAX 100 ///< maximum score |
| 464 | 464 | |
| 465 | 465 | #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer |
| @@ -212,10 +212,10 @@ const AVInputFormat *av_probe_input_format3(const AVProbeData *pd, · 211 unmodified lines | ||
| 212 | 212 | score = AVPROBE_SCORE_EXTENSION; |
| 213 | 213 | } |
| 214 | 214 | if (av_match_name(lpd.mime_type, fmt1->mime_type)) { |
| 215 | − if (AVPROBE_SCORE_MIME > score) { | |
| 216 | − av_log(NULL, AV_LOG_DEBUG, "Probing %s score:%d increased to %d due to MIME type\n", fmt1->name, score, AVPROBE_SCORE_MIME); | |
| 217 | − score = AVPROBE_SCORE_MIME; | |
| 218 | − } | |
| 215 | + int old_score = score; | |
| 216 | + score += AVPROBE_SCORE_MIME_BONUS; | |
| 217 | + if (score > AVPROBE_SCORE_MAX) score = AVPROBE_SCORE_MAX; | |
| 218 | + av_log(NULL, AV_LOG_DEBUG, "Probing %s score:%d increased to %d due to MIME type\n", fmt1->name, old_score, score); | |
| 219 | 219 | } |
| 220 | 220 | if (score > score_max) { |
| 221 | 221 | score_max = score; |
| @@ -244,7 +244,7 @@ static int read_probe_openmpt(const AVProbeData *p) · 243 unmodified lines | ||
| 244 | 244 | * AVPROBE_SCORE_MAX in order to reduce the impact in the rare |
| 245 | 245 | * cases of false positives. |
| 246 | 246 | */ |
| 247 | − return AVPROBE_SCORE_MIME + 1; | |
| 247 | + return (AVPROBE_SCORE_MAX * 3) / 4 + 1; | |
| 248 | 248 | } else if (probe_result == OPENMPT_PROBE_FILE_HEADER_RESULT_WANTMOREDATA) { |
| 249 | 249 | if (probe_openmpt_extension(p) > 0) { |
| 250 | 250 | return AVPROBE_SCORE_RETRY; |